中华放射医学与防护杂志
中華放射醫學與防護雜誌
중화방사의학여방호잡지
Chinese Journal of Radiological Medicine and Protection
2015年
11期
835-838
,共4页
刘乐乐%马阳光%李国文%郭跃信
劉樂樂%馬暘光%李國文%郭躍信
류악악%마양광%리국문%곽약신
非均整器模式%多叶准直器%到位偏差%调强放射治疗%剂量学
非均整器模式%多葉準直器%到位偏差%調彊放射治療%劑量學
비균정기모식%다협준직기%도위편차%조강방사치료%제량학
Flattening filter-free%Multi leaf collimator%Position error%Intensity radiotherapy%Dosimetry
目的 研究多叶准直器(MLC)整体到位偏差对均整器(FF)和无均整器(FFF)模式的鼻咽癌固定野调强计划剂量学影响的比较.方法 选取10例鼻咽癌患者,分别设计FF和FFF调强计划.修改两种计划的MLC文件,人为引入0.5和1 mm两种偏移量的3种MLC整体到位偏差.重新计算修改MLC文件后的调强计划的剂量分布,比较两种射束模式调强计划的剂量学变化趋势.结果 与FF计划比较,MLC整体闭合时,FFF计划的靶区D95％和两侧腮腺的Dmean对MLC到位偏差的敏感性稍高(t=3.298 ～4.793,P ＜0.05);MLC整体平移时,FFF计划靶区Dmean、D95％和左侧腮腺的Dmean对MLC到位偏差的敏感性稍高(t=2.372 ～6.844,P＜0.05),但是右侧腮腺的Dmean却表现出较低的敏感性(t=-4.049、-3.378,P＜0.05).结论 对于射野外的器官或体积较大器官,无均整器模式比均整器模式计划对MLC整体到位偏差表现出更高的敏感性.
目的 研究多葉準直器(MLC)整體到位偏差對均整器(FF)和無均整器(FFF)模式的鼻嚥癌固定野調彊計劃劑量學影響的比較.方法 選取10例鼻嚥癌患者,分彆設計FF和FFF調彊計劃.脩改兩種計劃的MLC文件,人為引入0.5和1 mm兩種偏移量的3種MLC整體到位偏差.重新計算脩改MLC文件後的調彊計劃的劑量分佈,比較兩種射束模式調彊計劃的劑量學變化趨勢.結果 與FF計劃比較,MLC整體閉閤時,FFF計劃的靶區D95％和兩側腮腺的Dmean對MLC到位偏差的敏感性稍高(t=3.298 ～4.793,P ＜0.05);MLC整體平移時,FFF計劃靶區Dmean、D95％和左側腮腺的Dmean對MLC到位偏差的敏感性稍高(t=2.372 ～6.844,P＜0.05),但是右側腮腺的Dmean卻錶現齣較低的敏感性(t=-4.049、-3.378,P＜0.05).結論 對于射野外的器官或體積較大器官,無均整器模式比均整器模式計劃對MLC整體到位偏差錶現齣更高的敏感性.
목적 연구다협준직기(MLC)정체도위편차대균정기(FF)화무균정기(FFF)모식적비인암고정야조강계화제량학영향적비교.방법 선취10례비인암환자,분별설계FF화FFF조강계화.수개량충계화적MLC문건,인위인입0.5화1 mm량충편이량적3충MLC정체도위편차.중신계산수개MLC문건후적조강계화적제량분포,비교량충사속모식조강계화적제량학변화추세.결과 여FF계화비교,MLC정체폐합시,FFF계화적파구D95％화량측시선적Dmean대MLC도위편차적민감성초고(t=3.298 ～4.793,P ＜0.05);MLC정체평이시,FFF계화파구Dmean、D95％화좌측시선적Dmean대MLC도위편차적민감성초고(t=2.372 ～6.844,P＜0.05),단시우측시선적Dmean각표현출교저적민감성(t=-4.049、-3.378,P＜0.05).결론 대우사야외적기관혹체적교대기관,무균정기모식비균정기모식계화대MLC정체도위편차표현출경고적민감성.
Objective To compare the dosimetric effects of systematic MLC leaf position errors on flattening filter (FF) and flattening filter-free (FFF) IMRT for nasopharyngeal carcinoma (NPC).Methods In totaly of ten patients with NPC were enrolled in the current study.FF IMRT and FFF IMRT plans were designed for each patient, and in-house software was developed to modify the corresponding MLC files.Briefly, three kinds of systematic MLC error presented with 0.5 and 1 mm magnitudes error were simulated.The modified MLC files were re-imported into IMRT plans for dose recalculation, and differences in the dosimetry trends between FF-IMRT and FFF-IMRT plans were analyzed using a dosevolume histogram.Results Upon closed MLC, the average changes in D95％ of PTV and D of parotid glands in FFF-IMRT plans were more sensitive than in FF-IMRT plans (t =3.298-4.793, P ＜ 0.05).Otherwise, when MLC are shifted in the same direction, changes in D95％of PTV, D of PGTV, PTV as well as D of left parotid gland in FFF-IMRT plans were also more sensitive (t =2.372-6.844, P ＜ 0.05), whereas average changes in D of right parotid gland presented with less sensitivity (t =-4.049,-3.378, P ＜ 0.05).Conclusions For out-of-field or large organs, FFF-IMRT plans are more sensitive to leaf position error than FF-IMRT plans.
